After studying philosophy and theology at the seminary of Recanati, he settled in Rome with an uncle who was a canon and pastor of San Lorenzo in Damaso.

He then studied at the Pontifical Roman Seminary and at La Sapienza University, from where he obtained doctorates in theology and in canon and civil law.

On the following March 26, he was named Prefect of Economy of the Congregation of Propaganda Fide and of the Reverend Chamber of Despoilments.

He served as Prefect of the Congregation for Studies from October 19, 1877 to August 9, 1878, and participated in the 1878 papal conclave, which elected Pope Leo XIII.

Leo XIII later appointed Nina as Vatican Secretary of State, essentially the prime minister of the Pope, on August 9, 1878.